If the US hopes to move the goods and people in wartime, the US has to repair our Merchant Marine:
If the Merchant Marine is to meet its responsibilities of supporting U.S. military forces, then it is time to take three major steps toward a more self-reliant Merchant Marine. It must: promote more employment and training opportunities; change the way it operates with the military; and make long-term investments for the American maritime industry over the next ten years.
I think part of supporting US-flagged merchant ships could involve subsidizing ships the way we do with aircraft in the Civil Reserve Air Fleet. If we had a pool of these subsidized ships that include container ships that are readied for easy conversion to auxiliary cruisers using systems housed in standard shipping containers, we'd have more ships for moving supplies and have some to spare for modularized auxiliary cruisers.
I described this idea for AFRICOM as a power projection platform in Military Review, but its roots are for a Navy asset.